Nuprl Lemma : word-rel-length

∀[X:Type]. ∀[w1,w2:(X + X) List].  ||w2|| < ||w1|| supposing word-rel(X;w1;w2)


Proof




Definitions occuring in Statement :  word-rel: word-rel(X;w1;w2),  length: ||as||,  list: T List,  less_than: a < b,  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  union: left + right,  universe: Type
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  uimplies: b supposing a,  word-rel: word-rel(X;w1;w2),  exists: ∃x:A. B[x],  and: P ∧ Q,  prop: ℙ,  true: True,  top: Top,  append: as @ bs,  all: ∀x:A. B[x],  so_lambda: so_lambda(x,y,z.t[x; y; z]),  so_apply: x[s1;s2;s3],  decidable: Dec(P),  or: P ∨ Q,  satisfiable_int_formula: satisfiable_int_formula(fmla),  false: False,  implies: P ⇒ Q,  not: ¬A,  squash: ↓T,  subtype_rel: A ⊆r B,  guard: {T},  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q
Lemmas referenced :  word-rel_wf,  member-less_than,  length_wf,  list_wf,  length-append,  list_ind_cons_lemma,  list_ind_nil_lemma,  length_of_cons_lemma,  length_of_nil_lemma,  decidable__lt,  satisfiable-full-omega-tt,  intformnot_wf,  intformless_wf,  itermAdd_wf,  itermVar_wf,  itermConstant_wf,  int_formula_prop_not_lemma,  int_formula_prop_less_lemma,  int_term_value_add_lemma,  int_term_value_var_lemma,  int_term_value_constant_lemma,  int_formula_prop_wf,  less_than_wf,  squash_wf,  true_wf,  iff_weakening_equal
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  introduction,  cut,  sqequalHypSubstitution,  productElimination,  thin,  hypothesis,  extract_by_obid,  isectElimination,  cumulativity,  hypothesisEquality,  sqequalRule,  isect_memberEquality,  unionEquality,  independent_isectElimination,  because_Cache,  equalityTransitivity,  equalitySymmetry,  universeEquality,  natural_numberEquality,  voidElimination,  voidEquality,  dependent_functionElimination,  addEquality,  unionElimination,  dependent_pairFormation,  lambdaEquality,  int_eqEquality,  intEquality,  computeAll,  applyEquality,  imageElimination,  imageMemberEquality,  baseClosed,  independent_functionElimination

Latex:
\mforall{}[X:Type].  \mforall{}[w1,w2:(X  +  X)  List].    ||w2||  <  ||w1||  supposing  word-rel(X;w1;w2)



Date html generated: 2017_01_19-PM-02_49_19
Last ObjectModification: 2017_01_14-PM-04_46_23

Theory : free!groups


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